APA (7th ed.) Citation

Sierra Leone. Survey Department, Great Britain. Ordnance Survey, & Great Britain. Directorate of Overseas Surveys. (1963). Sierra Leone (Ed. 6 GSGS.). D. Survey, War Office and Air Ministry.

Chicago Style (17th ed.) Citation

Sierra Leone. Survey Department, Great Britain. Ordnance Survey, and Great Britain. Directorate of Overseas Surveys. Sierra Leone. Ed. 6 GSGS. [London]: D. Survey, War Office and Air Ministry, 1963.

MLA (9th ed.) Citation

Sierra Leone. Survey Department, et al. Sierra Leone. Ed. 6 GSGS. D. Survey, War Office and Air Ministry, 1963.